<template>
  <div>
    <div class="goods">
        <div class="menu-wrapper" ref="menuWrapper">
          <ul>
            <li v-for="(item,index) in goods" :key="item.name" class="menu-item" :class="{'current':currentIndex===index}" @click="selectMenu(index)">
              <span class="text boder-1px">
                <span v-show="item.type > 0" class="icon" :class="classMap[item.type]"></span>{{item.name}}
              </span>
            </li>
          </ul>
        </div>
        <div class="foods-wrapper" ref="foodsWrapper">
          <ul>
            <!-- food-list-hook 表明这是一个被js选择的样式，并没有实际的效果 -->
            <li v-for="(item,index) in goods" class="food-list food-list-hook" :key="index.name">
              <h1 class="title">{{item.name}}</h1>
              <ul>
                <li @click="selectThisFood(food,$event)" v-for="food in item.foods" :key="food.icon" class="food-item border-1px">
                  <div class="icon">
                    <img width="57" height="57" :src="food.icon">
                  </div>
                  <div class="content">
                    <h2 class="name">{{food.name}}</h2>
                    <p class="desc">{{food.description }}</p>
                    <div class="extra">
                      <span class="count">月售1314份</span><span>好评率99%</span>
                    </div>
                    <div class="price">
                      <span class="now">￥{{food.price}}</span><span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                    </div>
                    <div class="cartcontrol-wrapper">
                      <cartcontrol @getAddButtonElements="takeAddButtonElements" :food="food"></cartcontrol>
                    </div>
                  </div>
                </li>
              </ul>
            </li>
          </ul>
        </div>
        <shopcart ref="shopcart" :select-foods="selectFoods" :delivery-price="seller.deliveryPrice" :min-price="seller.minPrice"></shopcart>
    </div>
    <food @sendButtonElment="getButtonElement" :food="selectedFood" ref="food"></food>
  </div>
</template>

<script>
// 导入better-scroll插件
import BScroll from 'better-scroll';
// 导入购物车shopcart.vue组件
import shopcart from '../shopcart/shopcart.vue';
// 导入cartcontrol组件
import cartcontrol from '../cartcontrol/cartcontrol.vue';
// 导入food组件
import food from '../food/food.vue';

const ERR_OK = 0;

export default {
  props: ['seller'],
  components: {
    shopcart: shopcart, // 注册shopcart组件到goods.vue身上
    cartcontrol: cartcontrol,
    food: food
  },
  data() {
    return {
      goods: [],
      listHeight: [],
      scrollY: 0,
      selectedFood: {}
    };
  },
  computed: {
    currentIndex() {
      for (let i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i];
        let height2 = this.listHeight[i + 1];
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          return i;
        }
      }
      return 0;
    },
    selectFoods() {
      let foods = [];
      this.goods.forEach((good) => {
        good.foods.forEach((food) => {
          if (food.count) {
            foods.push(food);
          }
        });
      });
      return foods;
    }
  },
  created() {
    this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee'];
    this.$http.get('/api/goods').then(res => {
      if (res.body.errno === ERR_OK) {
        this.goods = res.body.data;
        // console.log(this.goods);
        this.$nextTick(() => {
          this._initScroll();
          this._calculateHeight();
        });
      }
    });
  },
  methods: {
    getButtonElement(element) {
      this.takeAddButtonElements(element);
    },
    takeAddButtonElements(element) {
      // console.log(this.$refs.shopcart);
      this.$refs.shopcart.drop(element);
    },
    selectThisFood(food, event) {
      this.selectedFood = food;
      this.$refs.food.show(); // 调用子组件food中的方法
    },
    selectMenu(index) {
      console.log(index);
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let el = foodList[index];
      this.foodScroll.scrollToElement(el, 1000);
    },
    _initScroll() {
      this.menuScroll = new BScroll(this.$refs.menuWrapper, {
        click: true // 让betterScroll操控的页面可以点击
      });
      this.foodScroll = new BScroll(this.$refs.foodsWrapper, {
        click: true, // 让betterScroll操控的页面可以点击
        probeType: 3 // BetterScroll 实时派发 scroll 事件，是需要设置 probeType 为 3。
      });
      this.foodScroll.on('scroll', (pos) => {
        this.scrollY = Math.abs(Math.round(pos.y));
      });
    },
    _calculateHeight() {
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let height = 0;
      this.listHeight.push(height);
      for (let i = 0; i < foodList.length; i++) {
        let item = foodList[i];
        height += item.clientHeight; // 每个区间对应的高度，每个区间的高度 = 自身区间高度 + 前一个区间的高度
        this.listHeight.push(height);
      }
    }
  }
};
</script>

<style lang="stylus" scoped>
  @import "../../common/stylus/mixin.styl";

  .goods
    display flex
    position absolute
    top 174px // header134px + tab40px
    bottom 46px //底部有个购物篮46px高度
    width 100%
    overflow hidden
    .menu-wrapper
      flex 0 0 80px
      width 80px
      background #f3f5f7
      .menu-item
        display table // 容器中的文字不管几行都会做到垂直居中
        height 54px
        width 56px
        padding 0 12px
        // color rgb(240,20,20)
        line-height 14px
        &.current
          position relative
          z-index 10
          margin-top 1px
          // background #fff
          background rgba(47,154,81,0.4)
          color #fff;
          font-weight 700
          .text
            border-none()
        .icon
          display inline-block
          width 12px
          height 12px
          vertical-align top
          margin-right 2px
          background-size 12px 12px
          background-repeat no-repeat
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')
          &.guarantee
            bg-image('guarantee_3')
          &.invoice
            bg-image('invoice_3')
          &.special
            bg-image('special_3')
        .text
          display table-cell
          width 56px
          vertical-align middle
          border-1px(rgba(7,17,27,0.1))
          font-size 12px
    .foods-wrapper
      flex 1
      .title
        padding-left 14px
        height 26px
        line-height 26px
        border-left 2px solid #d9dde1
        font-size 12px
        color rgb(147,153,159)
        background #f3f5f7
      .food-item
        display flex
        margin 18px
        padding-bottom 18px // 上下margin会进行重叠，需要单独设置一个bottom值
        border-1px(rgba(7,17,27,0.1))
        &:last-child //最后的一个孩子元素
          boder-none() // 消除边框
          margin-bottom 0
        .icon
          flex 0 0 57px
          margin-right 10px
        .content
          flex 1
          .name
            margin 2px 0px 8px 0px
            height 14px
            line-height 14px
            font-size 14px
            color rgb(7,17,27)
          .desc, .extra
            line-height 10px
            font-size 10px
            color rgb(147,153,159)
          .desc
            line-height 12px
            margin-bottom 8px
          .extra
            .count
              margin-right 12px
          .price
            font-weight 700
            line-height 24px
            .now
              margin-right 18px
              font-size 14px
              color rgb(240,20,20)
            .old
              text-decoration line-through
              font-size 10px
              line-height 24px
              color rgb(147,153,159)
          .cartcontrol-wrapper
            position absolute
            right 0
            bottom 12px
</style>
